High Magnesium and Dwarf Cuttles

In planning for my S. Bandensis tank, one of the things about my water chemistry is that I have been using a reef salt and I have a slightly elevated level of Magnesium: 1400 ppm (according to my ELOS kit). Is this going to be an issue? I remember reading a thread (here) that stated the cuttles had trouble hunting and he thought it was related to using a new salt mix (ESV) with elevated levels of Mg.

1400 should be fine, though it seems a bit too high (1220-1350 is the general level to shoot for)- is that just from the salt mix? That said, Mg tests have a large margin of error - plus or minus 100 ppm.

Yes, from the salt mix, the company, ESV, targets 1400ppm Mg at 34ppt for this 4 part salt mix (http://www.esvco.com/B-IonicSeawaterNov.pdf). I like it because I can make 55 gallons and I am done mixing in 5 minutes and it is ready after an hour of aeration.